Digger tooth locking pin



Oct. 22, 1968 G. DUPLESSIS 3,406,471

DIGGER TOOTH LOCKING PIN Filed Dec. 1, 1966 PATENT AGE/V7 United StatesPatent ice The presentinvention "relates to two-partdigger or excavatingteeth for the bucket of power shovels andthe like and, morespecifically, to a locking pin of improved together. v V Excavatingteeth of the cha'racterdescribed consist of an adapter having a'forwardly protrudingtapered nose, on which is fitteda tooth point forreceiving the nose. 1

The tooth point is provided with aligned openings adapted to registerwith a transverse bore made in'the nose for receiving a locking key orpin, which maintains and locks the tooth point in position on the nose.A block of compressible material is-positioned in a cavity within thenose and protrudes into'thebore "to engage and press the locking pin so'as to prevent accidental removal or displacement of the pin.-'-However,

design for securing the two parts of "the excavating tooth due to thehigh stresses and forces impartedto the nose and tooth point duringdigging; due also tothe fact that the tooth point and adapter are castmetal pieces which therefore, are not'manufactu'red to very closetolerances; and, finally, due to the fact of metal creeping especiallyof the tooth point during working, displacement of the locking pin stillfrequently happens, resulting in break: age of the adapter and/or toothpoint, or resulting in a locking pin which is impossible to remove forreplacing the worn tooth point. i Y

The general object of the present invention resides, therefore, in alocking pin whichis of improved design such that when in proper lockingposition, it 'is"pra'c tically impossible for the locking pin to'become'acci dentally dislodged from its intended'operative' position and whichyet can'berelatively'easilyremoved is desired to replace the worn-outtooth point.

A more specific object of the present invention resides in the provisionof a locking keyor pin of the character described, which is' providedwith'an upwardly facing having a tapered socket step at its back facetopreventdisplacement of the locking pin upwardly and which isprovidedat its front face with anotched medial rib of less .widthzthan-the-total width of the front face of the pin,-,-said notch beingcharacterized by the fact that the bottom thereof'iswoextensive with thefront face of the pin, whereby the pres- F sure, namely the force perunit area, exerted by the compression block on the pin is much greaterwhen the pin is forced out of its normal positionandsengagesonly the ribthan when it is in its normal-positionyinfwhich position the forceexerted by the bolck on the pin extends over the entire width of thefront face of the pifilaTherel fore, the friction is greater. in theabove-noted displaced position and the pin is positively maintained inits iritende'd operative position, so that there is assurance that thekey will never become improperly positioned resulting in breakage of theadapter or tooth point, or of the distortion or bending of saidelements, such that it would be impossible to remove the locking pin.

The foregoing and other important objects ofthe present invention willbecome more apparent during the following disclosure and by referring tothe drawings, in which:

FIGURE 1 is a partial view of an adapter, tooth point, locking pin andretaining compressible block, shown partially in elevation and partiallyin longitudinal section;

- axis. Said face portion 9 is straight and fiat.

3,406,471 Patented Get. 22, 1 968 FIGURE 2 is a side elevation ofthelockingpin; FIGURE 3 is a front elevation of the locking pin; F FIGURE 4is a partial top plan view of. the assembly of'FIGURE 1;and '1 r FIGURE5 is a partial 5-5 of FIGURE 1. 4

Referring now more particularly to the drawings in which like referencecharacters indicate like elements throughout, the locking pin P inaccordance with the present invention consists of an elongatedfour-sided bodyfihaving substantially fiat and parallel lateral faces 1,substantially flat front face 2 andba'ck face 3,a substan-' tially flattop face 4 downwardly and forwardly inclined relative to the long axisof the pin, and a roundedlower end face 5. The four longitudinal edgesofthe pin are bevelled, as shown at 6 and 7,*-for the front bevelled'edges' and back bevelled edges respectively and, similarlygthe' lateraledges of the top face 4 are bevelled as shown-at 8. :c The upper zone ofthe pin P forms a recessed back face portion 9 with respect to theremaining portion'of back face 3, to thereby define an upwardly facing'step 10 at substantially right angles to the long axis of the pin P.The recessed face portion 9 is upwardly forwardly inclined with respectto the long axis of pin P, so as to make angle of between 7 and 10degrees with said long plan section taken along line Thelower portion offront face 2 is downwardly and rearwardly inclined, as shown at 11, sothat the corre* sponding lower end portoin of the pin is tapered towardslower end face 5. I

A longitudinally extending central rib 12 protrudes forwardly from frontface 2 and extends over the major part of the length of said front face.More particularly, rib 12 defines an upper portion 13 and a lowerportion 14 separated by a curved notch '15, the bottom of which iscoincident with the front face 2, so as to lie in a sur face having thefull width of front face 2, contrary to -the remaining surface portionof notch 15 which only has the width of the rib 12, the latter beingabout /3 the width of face 2. I The lower rib portion 14 forms ahalf-part of notch 15 and gradually downwardly tapers to merge with thefront face 2 at the junction thereof with the lower front face 11.Actually, the front face of the lower rib portion -14 is aligned withlower face portion 11.

Upper rib portion 13 is of uniform thickness so that its front face isparallel with front face 2 and extends right up to the top face 4 of pinP, such that the top edge of the upper rib portion 13 forms thecontinuation of said top face 4.

The locking pin in accordance with the invention is used for locking thetwo parts of an excavating tooth, such as shown in the drawings. Saidexcavating tooth comprises an adapter 20, adapted to be removablysecured to the lip of a bucket of a power shovel or the like and havinga forwardly protruding integral tapered nose 21, on which is removablyfitted a tooth point 22 having a tapered socket for receiving nose 21.i' A In the fitted position. of the tooth point on nose 21, the freeedges 23 of the tooth point are slightly spaced from the shoulders 24defined between nose 21 and adapter main body 25.

Tooth point 22 is provided with aligned top and bottom holes 27 and 28,respectively, adapted to register, when the tooth point is in fittedposition, with a bore 29, made through nose 21, and opening at the topand bottom faces of said nose 21.

In the front face of bore 29 is defined a groove 30 opening at the topand bottom faces of nose 21 and in the bore 29. Groove 30 has a widthsmaller than the width of bore 29 and is centrally located with respectto said boressueh that -the groove -30 defines shoulders-" move 'th'etop-ofthe" pin forwardly' in orderto" help clear 31 on each sidethereof, said shoulders constituting the front face of the bore 29.

A block of compressible material, shown 'at 32, is located within groove30 and is tightly fitted therein. Preferably, the block- 32 has adovetailed base portion 33 engaging with a dovetailed bottom portion ofthe recess 30, in order to prevent disengagement compressible material32. Said block -32 is provided vat mid-length with a'boss 34 protrudingwithin bore 29 and-in which ispreferably embeddeda cylindrical metalblock, not shown, forming a .Wear surface forengagement with the lockingpin. 1

In the assembled position of the tooth point '22 on nose '21, the tophole 27 is forwardly offset with respect to bore 29, such that the backwall of top hole 27 is for- Wardly disposed ,With respect to the backwall of bore of theblock of 29 so as to form a downwardly facing step35, atthe junction of.the tooth point with the nose. -,Upo n insertionof the lowerpointed end 5 ofthe locking-pin through the top hole 27-ofthe tooth point 22 and then through bore 29,;with the locking pin in adownwardly and backwardly inclined position, the front face 2 of the pinat the lower end thereof engages the top edge ,of the front face 31 ofthe bore 29 on both sides of the compressible block 32, and the taperedlower face portion 11 engages the top edge of the compression block 32and initiates compression of said block. The back face 3 of the pinengages the back face of the top hole 27 and the pin, during saidinitial portion of the insertion, being in metal-to-rnetal contact withthe nose and tooth point 22, produces a firm fitting of the tooth pointon the noses Hammering of the locking pin causes the boss 34. of thecompressible block 32 to slide on the lower rib portion 14 until saidboss engages notch 15. Rib 12 compresses block 32 and engages groove 30.Step of the locking pin snaps underneath step 35 of tooth point 22. Inthe fully inserted position of the locking pin, as shown in FIGURE 1,the latter is prevented from accidentally moving upwardly because step 6engages step 35 in metalto-metal contact, thereby latching the lockingpin against upward movement, and also boss 34 engages notch 15 of e thelocking pin, which forms a second latching means for the locking pin,the lower rib portion 14 preventing upward displacement of the pin.

Conversely, the locking pin is prevented from downward movement becausethe boss 34 of the compressible block 32, engaged in notch 15, abuts theupper rib portion 13., t

The block 32 exerts a balanced rearward force on the top and bottom ofthe tooth point. 7

In the fully inserted position of the pin, the front face of the latteris free of any contact with the front face of the openings 27 and 28.

, The locking pin is relatively easily removed by hammering its lowerend 5, whereby step 10 will finally clear stop 35 and boss 34 of theblock 32 will clear the lower 1 rib portion 14.

If, for any reason, difficulty is experienced in having step 10.,clearstep 35, a screwdriver or other implement can be wedged between the backface of top hole 27 and the inclined recessed back face portion 9 of thepin to step 10.

Due to the above-noted latching feature of the locking pin in accordancewith the invention, to prevent both downward and upward rnovement of thelatter from its intended position, it'has been found that the pin inaccordance with' the invention remains in 'position despite heavystressesto which the digging tooth is subjected dursus '1 While apreferred embodiment in accordance with the present inventionhas beenillustrated and described, it is understood that various modificationsmay be resorted to without departing from, the spirit and scope of theappended claims. v v

- What [claim is:

1. Alocking pin for a two-part excavating tooth, comprising an elongatedsolid four-sided body having substantially. fiat lateral faces andhaving front and back faces, a pointed lower end and a top end face,said, back face having. a recessed upper face portion defining anupwardly facing step located nearer said topface than said lower end, alongitudinal rib protruding medially of said'front face and extendingfrom said top end facedownwardly-toward said lower. end below the levelof said step, saidrib having a notch made therein intermediate itsendsvand disposed below the level of said step, the bottom of said notchcoinciding with a surface extending substantially the full width of saidpin.

-. 2. A locking pin as claimed in claim 1, wherein said recessed upperface portion is upwardly forwardly inclined with respect to thelongitudinal axis of said pin.

3. A locking pin as claimed in claim 1, wherein said rib has a widthequal to about one-third of the total width of said body.

4. A locking pin as claimed inclaim 1, wherein said notch is locatedatabout substantially midlength of said yp 5. A locking pin as claimed inclaim 4, whereinthe portion of said rib below said notch has a frontface downwardly tapering and merging with the front face of saidbody ata point short of the lower end of said body, the front face of said bodybeing inclined downwardly and rearwardly from the point of junction ofthe front face of said rib,with. said front face of said body to thelower end of said body, said inclined front face portion being inalignment vwith the inclined front face of the lower rib portion. .1

ReferencesiCited v 1 UNITED STATES PATENTS 2,674,816 4 /1954 Daniels-ctal. 37-442 2,904,908 9/ 1959 Ratowski 37-142 2,982,035 5/1961Stephenson' 3 7142 2,990,634" 7/ 1961 Eyolf son 37- 142 2/1968 Judkihset 'al. 37-142 V I ,,F OREIGN PAYTENTSY 1;: 565,417: 11/1944 England;641,404 5/1962- Canada.

aonER-"r nt-ruLrnnvgrl-imar Exam i ner.

1. A LOCKING PIN FOR A TWO-PART EXCAVATING TOOTH, COMPRISING ANELONGATED SOLID FOUR-SIDED BODY HAVING SUBSTANTIALLY FLAT LATERAL FACESAND HAVING FRONT AND BACK FACES, A POINTED LOWER END AND A TOP END FACE,SAID BACK FACE HAVING A RECESSES UPPER FACE POTION DEFINING AN UPWARDLYFACING STEP LOCATED NEARER SAID TOP FACE THAN SAID LOWER END, ALONGITUDINAL RIB PROTRUDING MEDIALLY OF SAID FRONT FACE AND EXTENDINGFROM SAID TOP END FACE DOWNWARDLY TOWARD SAOD LOWER END BELOW THE LEVELOF SAID STEP, SAID RIB HAVING A NOTCH MADE THEREIN INTERMEDIATE ITS ENDSAND DISPOSED BELOW THE LEVEL OF SAID STEP, THE BOTTOM OF SAID NOTCHCOINCIDING WITH A SURFACE EXTENDING SUBSTANTIALLY THE FULL WIDTH OF SAIDPIN.